1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Cat symbols

Discussion in 'Shop Talk' started by partsandservice, Nov 30, 2019.

  1. check

    check Senior Member

    Joined:
    Apr 1, 2012
    Messages:
    722
    Location:
    in the mail
    The size of the market and the relative low cost of doing so.
     
  2. John C.

    John C. Senior Member

    Joined:
    Jun 12, 2007
    Messages:
    6,728
    Occupation:
    Machinery & Equipment Appraiser
    Location:
    Northwest
    I think Mr. RZucker is where I would start the problem process. Model year of the machine is 2007. All the dead bugs in the photo indicates possible wiring harness problems along with all the prior suggestions. In the past, I've used an ohm meter on the highest setting probing harness connections looking for cross connectivity between wires caused by oil breaking down the insulation inside the harness.
     
  3. partsandservice

    partsandservice Senior Member

    Joined:
    Feb 14, 2011
    Messages:
    646
    Location:
    Georgia
    Customer install new injector engine harness ( left side ecu connecter). I installed used harness (right side)with identical part # and nothing changed. I did back probe the ground signal wire to fuel supply pump relay. I only checked that wire to frame ground, when the relay is activated there is high resistance to frame ground and no resistance when it kicks out. So I got it stuck in my head that the ecu has a ground issue. But I am going to use all advise given.
     
  4. partsandservice

    partsandservice Senior Member

    Joined:
    Feb 14, 2011
    Messages:
    646
    Location:
    Georgia
    So this morning I load checked the voltage and ground supply to ECU. Ok
    Load check key switch input wire ok. Check all ground points and straps. Installed known good ecu . Key switch on , all clicking gone. Engine fired right up. Thanks again for the help.
     
  5. Mike L

    Mike L Senior Member

    Joined:
    Dec 1, 2010
    Messages:
    623
    Occupation:
    Self employed field mechanic
    Location:
    maine
    Do you use a load pro to load check your circuits?
     
  6. partsandservice

    partsandservice Senior Member

    Joined:
    Feb 14, 2011
    Messages:
    646
    Location:
    Georgia
    Yes I used a load pro to emulate the ecu draw. When load checking the ecu voltage supply circuit it showed minute voltage drop between the positive and negative supply wires to ECU. Voltage drop was the same when checking positive ecu supply to frame ground. Which told me that circuit was good. Most probably know this but you should never use load pro to check ecu inputs. When ever I think that there is a wiring issue with an ecu input wire I disconnect the both ends , the sensor and ecu connecter, and use a light bulb to load test that wire.